TWI663345B - Cycloidal reducer and eccentric gear assembly for cycloidal reducer - Google Patents

Abstract

The invention includes a fixed housing, an input shaft, an eccentric shaft, an eccentric gear and an output shaft. The fixed casing has a cylindrical ring gear portion and an axis line; the cylindrical ring gear portion has N cylinders and a ring gear radius R. The input shaft is arranged on the fixed housing and is coaxial with the shaft center line, and can rotate along the shaft center line; and there is an eccentricity E between the input shaft and the eccentric shaft. The eccentric shaft is provided on an eccentric gear; the eccentric gear corresponds to N cylinders and has M cycloidal teeth, and ; Each cycloidal tooth portion includes an outwardly convex arc portion and an inwardly concave arc portion, a corner portion is formed therebetween; the output shaft is fixed to the eccentric gear. The input shaft drives the eccentric gear through the eccentric shaft, so that the M cycloidal teeth rotate along N cylinders, and finally outputs the output speed through the output shaft. This case has the advantages of better power transmission efficiency, reduced backlash, and reduced tooth surface wear.

Description

Cycloidal reducer and eccentric gear assembly for cycloidal reducer

The present invention relates to a cycloidal reducer and an eccentric gear assembly for a cycloidal reducer, and more particularly to a cycloidal reducer and a oscillating reducer that have better power transmission efficiency, can reduce backlash, and can reduce tooth surface wear. Eccentric gear assembly for linear reducer.

Cycloidal reducer has the advantages of high deceleration, high rigidity and low backlash. Referring to FIGS. 1A and 2, the cycloid reducer system includes: a fixed housing 10 having a first hole 11 and a cylindrical ring gear portion 12. The first hole 11 has an axis line X; the cylindrical ring gear portion 12 has N cylinders 121 and a ring gear radius R; wherein N is a positive integer. An input crank 20 is provided with an input shaft 21 and an eccentric shaft 22. The input shaft 21 is pivoted on the first hole 11 and is rotatable along the axis line X; the input shaft 21 and the eccentricity There is an eccentricity E between the shafts 22; the input shaft 21 has an input speed. An eccentric gear 30 has a second hole 31, and the eccentric shaft 22 is pivotally disposed in the second hole 31. The eccentric gear 30 corresponds to N cylinders 121 and has M cycloid teeth 32, where M is a positive integer less than N, and . An output shaft 40 is fixed to the eccentric gear 30. The output shaft 40 has an output speed. The M cycloidal teeth 32 include: M outward convex arc portions 321; M inner concave arc portions 322. Each of the outwardly convex arc portions 321 and the adjacent inwardly concave arc portion 322 are smoothly connected. This design results in a smaller effective component force during power transmission. Because when the cycloid tooth 32 contacts the cylinder 121, the common normal of the contact points is the direction of force transmission. As shown in Figure 10A, in the conventional cycloid reducer, when the transmission force is F11, The pressure angle is θ1. In the case of FIG. 10A, the pressure angle θ1 is about 60 degrees. Therefore, its effective component force F12 = F11xcosθ1 = 0.5 times F11, in short, only about half (50%) is effective. Therefore, it is very disadvantageous when applied to high torque transmission. In addition, the traditional cycloid reducer belongs to the design of small eccentricity. At present, there is no design of large eccentricity on the market. If you want to generate the trochoidal tooth profile in Figure 2, in addition to drawing the trajectory with a geometric formula, you can also first find the tool path (as shown in Figure 3, that is, the tool trajectory L). The cylindrical 121 of the cylindrical ring gear portion 12 has the same diameter. When the cutter passes the design path around the eccentric gear 30 once, the tooth profile drawn or cut out is a cycloid tooth profile. In view of this, it is necessary to develop technologies that can solve the above-mentioned conventional disadvantages.

The purpose of the present invention is to provide a cycloid reducer and an eccentric gear assembly for the cycloid reducer, which has the advantages of better power transmission efficiency, lower backlash, and reduced tooth surface wear. In particular, the problems to be solved by the present invention are the poor transmission efficiency of traditional cycloidal reducers, and the design of small eccentricity. The technical means for solving the above problems is to provide a cycloid reducer and an eccentric gear assembly for the cycloid reducer, which includes: a fixed casing having a first hole and a cylindrical ring gear portion; the first hole system It has an axis line, the cylindrical ring gear part has N cylinders and a ring gear radius R; wherein N is a positive integer; at least one input crank has an input shaft and an eccentric shaft, and the input shaft system is pivoted On the first hole and rotatable along the axis of the shaft; an eccentricity E between the input shaft and the eccentric shaft; an eccentric gear having at least a second hole, the eccentric shaft is pivoted on The second hole; the eccentric gear corresponds to N cylinders and has M cycloid teeth, wherein M is a positive integer less than N, and ; Each cycloidal tooth portion includes an outwardly convex arc portion and an inwardly concave arc portion, each of the outwardly convex arc portions and an adjacent inwardly concave arc portion form a corner portion, and the number of the corner portions There are 2M gears; an output shaft is fixed to the eccentric gear; thereby, the input shaft is rotated at an input speed, the eccentric gear is driven through the eccentric shaft, and the M cycloid teeth are along the N The cylinder rotates, and finally outputs an output speed through the output shaft. The above-mentioned objects and advantages of the present invention can be easily understood from the detailed description and accompanying drawings of selected embodiments below. The following examples and drawings are used to explain the present invention in detail:

Referring to Figures 1A, 1B, 2, 3, and 7, the present invention is a cycloid reducer (also known as a cycloid gear reducer) and an eccentric gear assembly for a cycloid reducer, which includes: The fixed casing 10 has a first hole 11 and a cylindrical ring gear portion 12. The first hole 11 has an axis line X; the cylindrical ring gear portion 12 has N cylinders 121 and a ring gear radius R; wherein N is a positive integer. At least one input crank 20 has an input shaft 21 and an eccentric shaft 22. The input shaft 21 is pivoted on the first hole 11 and can rotate along the axis line X. The input shaft 21 and the eccentricity There is an eccentricity E between the shafts 22. An eccentric gear 30 is provided with at least a second hole 31 (to avoid confusion in the drawing, the second hole 31 in FIG. 1B is omitted and not shown), and the eccentric shaft 22 is pivoted on the第二 孔 31。 The second hole 31. The eccentric gear 30 corresponds to N cylinders 121 and has M cycloid teeth 32, where M is a positive integer less than N, and . Each of the cycloidal tooth portions 32 includes an outwardly convex arc portion 321 and an inwardly concave arc portion 322; a corner portion 320 is formed between each of the outwardly convex arc portions 321 and an adjacent inwardly concave arc portion 322, The number of the corner portions 320 is 2M. An output shaft 40 is fixed to the eccentric gear 30. Thereby, the input shaft 21 is rotated at an input speed, the eccentric gear 30 is driven through the eccentric shaft 22, the M cycloid teeth 32 are rotated along the N cylinders 121, and finally an output shaft is provided through the output shaft 40. Output speed. In practice, the focus of this case is: [a] The eccentric gear 30 corresponds to N cylinders 121 and has M cycloid teeth 32, where M is a positive integer less than N, and . [b] Each of the cycloidal teeth portions 32 includes an outwardly convex arc portion 321 and an inwardly concave arc portion 322 (see FIG. 7). A corner portion 320 is formed between each of the convex convex portions 321 and the adjacent concave concave portion 322. The number of the corner portions 320 is 2M. The corner portion 320 has an angle T. The angle T is between 80 and 100 degrees (as shown in FIG. 10B, it is a reference diagram slightly less than 90 degrees). The cylinder 121 has a pressure angle θ2 corresponding to the corner portion 320 and the concave arc portion 322, which is less than 30 degrees, which can improve the effective component force (cos30 degrees is about 0.87, that is, the effective component force accounts for about 90%). To improve the efficiency of power transmission. Regarding the design (manufacturing process) of the tooth profile with a large eccentricity amount in this case (that is, the eccentric gear 30), the procedure is as follows: [a] First procedure: The N cylinders 121 of the cylindrical ring gear portion 12 are regarded as Circumscribed, draw a tool path L as shown in Figure 4. [b] Second program: Make a tool (not shown in the figure, together with Chenming) follow the tool trajectory L to cut out the tooth profile as shown in Figure 5, and some of the tooth profiles are in the tool Repeat cutting while walking, and keep track of the repeated cutting in Figure 5. [c] Third program: Finally, leaving the contour of the cycloidal tooth portion 32 to obtain a clean tooth profile, as shown in FIG. 6, where the number of the cylinder 121 is 13 (N = 13 ), And the cycloidal teeth 32 have 12 (M = 12), of course, this number can be increased or decreased elastically. [d] The fourth program: refer to FIG. 7, which is a simulation diagram illustrating the corresponding cooperation of the M cycloid teeth 32 and the N cylinders 121 of the cylindrical ring gear portion 12. The cycloid teeth in the figure Although 32 has a turning point of about 90 degrees (that is, the angle T of the corner 320), the tool path is very smooth, and there is no difficulty in actual processing. It is worth noting that although the tool trajectory of FIG. 4 is not the first sight, applying this trajectory to the tooth profile of the cycloidal tooth portion 32 (ie, the cycloid gear) should be unprecedented. For example, when it is within the following conditions: the cylinder 121 is 18 (that is, N = 18). The ring gear radius R is 50 mm. The cylinder 121 has a radius r, which is 3 mm. The eccentricity of the traditional cycloidal gear can only be up to 2.76mm, but the eccentricity of the cycloidal gear made by the present invention can reach 7mm (see Table 1 below). Table I sequence 1 2 3 4 5 6 7 E (mm) 1 2 2.76 (traditional threshold) 4 5 6 7 Please refer to FIG. 11, which is a physical picture 1 of the case, and shows the eccentric gear 30 processed by itself. Please refer to Figure 12, this is the real picture 2 of this case, which shows the finished product after self-processing and assembly. The advantages and effects of the present invention are as follows: [1] Power transmission efficiency is better. Generally, the pressure angle of traditional cycloidal gears is larger than that of involute gears, which is between 50 degrees and 90 degrees, and the larger the pressure angle, the smaller the force arm between the gear's force point and the rotating shaft, that is, The lower the effective component force. This case is designed for a large eccentric trochoid gear (ie, the eccentric gear 30). As shown in FIG. 10B, it is assumed that at least a part of the cylinder 121 is in contact with the concave arc portion 322 during operation. The common normal of the contact point is the direction of force transmission. When the transmission force is F11, the pressure angle (pressure angle θ2, about 30 degrees or less) is small, and its effective component force F12 = F11xcosθ1 = 0.87 times (approximately). F11 has a higher effective component (about 90%). Conducive to high torque transmission; therefore, power transmission efficiency is better. [2] Reduce backlash. There must be a margin of fit between the cycloid gear and the ring gear to avoid interference. As the number of teeth or the amount of eccentricity increases, the backlash decreases. However, the allowable value of the eccentricity decreases with the increase of the number of teeth. Therefore, in the traditional cycloid gear design, increasing the number of gears cannot reduce the backlash. As shown in Figure 8A, it is the eccentricity E of the traditional cycloid gear design, and Figure 8B shows that under the condition of the same number of teeth and radius, this case has a larger eccentricity E (at least 2 of the traditional device). Times). [3] Reduces wear on tooth surfaces. As shown in Figure 9A, the conventional cycloidal gear is designed to contact the "outer circle" to the "column" (or the "outer arc" to the "cylindrical"). In contrast to Figure 9B, the cycloid gear in this case is designed to have a majority of "hole" to "column" (or "concave arc" to "cylindrical") contact; therefore, it can reduce the wear of the tooth surface and avoid Increased backlash due to increased backlash after operation. The above is only a detailed description of the present invention through a preferred embodiment, and any simple modifications and changes made to the embodiment will not depart from the spirit and scope of the present invention.

10‧‧‧Fixed case

11‧‧‧ the first hole

12‧‧‧ Cylindrical ring gear

121‧‧‧Cylinder

20‧‧‧ input crank

21‧‧‧input shaft

22‧‧‧eccentric shaft

30‧‧‧eccentric gear

31‧‧‧ second hole

32‧‧‧ cycloid tooth

320‧‧‧ Corner

321‧‧‧ convex arc

322‧‧‧Recessed arc

40‧‧‧output shaft

R‧‧‧ ring gear radius

X‧‧‧ axis line

E‧‧‧eccentricity

T‧‧‧angle

θ1, θ2‧‧‧ pressure angle

L‧‧‧tool path

F11‧‧‧Transfer Force

F12‧‧‧ Effective component force

Figure 1A is a schematic diagram of the mechanism of the cycloid reducer. Figure 1B is a schematic diagram of other angles of Figure 1A. Figure 2 is a schematic diagram of the corresponding relationship of some structures in Figure 1A. The schematic diagram of the tooth profile. FIG. 4 is a schematic diagram of one of the manufacturing processes of the eccentric gear of the cycloid reducer of the present invention. The third schematic diagram of the manufacturing process of the eccentric gear of the cycloid reducer. Figure 7 is a schematic diagram of the completed eccentric gear of the cycloid reducer of the present invention. Figure 8A is a schematic diagram showing the eccentricity of the traditional cycloid gear design. The figure is a schematic diagram showing that the present invention has a large eccentricity. Figure 9A is a schematic diagram of the tooth surface contact state of a conventional device. Figure 9B is a schematic diagram of the tooth surface contact state of the present invention. Figure 10A is a partially enlarged schematic diagram of Figure 9A. Figure 10B is a part of Figure 9B. Enlarge the schematic diagram. Figure 11 is a schematic diagram of the physical photo of the present invention. Figure 12 is a schematic diagram of the physical photo of the present invention.

Claims (6)

A cycloid reducer includes: a fixed casing having a first hole and a cylindrical ring gear portion; the first hole having an axial line; the cylindrical ring gear portion having N cylinders and a ring Gear radius R; where N is a positive integer; at least one input crank has an input shaft and an eccentric shaft, the input shaft is pivoted on the first hole and can be rotated along the axis of the shaft; the input There is an eccentricity E between the shaft and the eccentric shaft; an eccentric gear has at least a second hole, and the eccentric shaft is pivoted at the second hole; the eccentric gear corresponds to N cylinders and has M pendulums Wire teeth, where M is a positive integer less than N, and E> (R / N); each cycloidal tooth system includes a convex convex portion and a concave concave portion, and each convex convex portion A corner portion is formed between the portion and the adjacent concave arc portion, and the number of the corner portions is 2M; an output shaft is fixed to the eccentric gear; thereby, the input shaft is rotated at an input speed , Driving the eccentric gear through the eccentric shaft, the M cycloidal teeth rotate along the N cylinders, and finally supplies through the output shaft Output an output speed. The cycloid reducer according to item 1 of the scope of patent application, wherein: the corner portion has an angle; the angle is between 80 and 100 degrees. According to the cycloid reducer described in item 1 of the scope of patent application, wherein the cylinder corresponds to the corner portion and the concave arc portion, and has a pressure angle, which is less than 30 degrees, which can improve the effective component force, and further Improve power transmission efficiency. An eccentric gear assembly for a cycloid reducer comprises: a cylindrical ring gear portion, which includes N cylinders and a ring gear radius R, wherein N is a positive integer; an eccentric gear is connected to the cylindrical ring gear portion Between them, there is an eccentricity E; the eccentric gear corresponds to N cylinders and has M cycloid teeth, where M is a positive integer less than N and E> (R / N); The tooth system includes an outwardly convex arc portion and an inwardly concave arc portion; a corner portion is formed between each of the outwardly convex arc portions and an adjacent inwardly concave arc portion, and the number of the corner portions is 2M. The eccentric gear assembly for the cycloid reducer according to item 4 of the scope of patent application, wherein: the corner portion has an angle; and the angle is between 80 and 100 degrees. According to the eccentric gear assembly for the cycloid reducer as described in item 4 of the scope of patent application, wherein the cylindrical system corresponds to the corner portion and the concave arc portion, and has a pressure angle, which is less than 30 degrees, which can improve Effective force distribution, which improves the efficiency of power transmission.